Turbine engine system with shafts for improved weight and vibration characteristic

Abstract

A method for assembling a turbine engine assembly is provided. The turbine engine includes a core engine. The method includes coupling a first rotor spool within the engine assembly wherein the first rotor spool includes a first shaft. The method further includes coupling a second rotor spool within the engine assembly wherein the second rotor spool includes a second shaft. The method also includes coupling a third rotor spool within the engine assembly wherein the third rotor spool includes a third shaft. At least one of the first, second, and third shafts include a first end, an opposing second end, and a tubular portion extending between the first and second ends. A reinforcing layer circumscribes a portion of the tubular portion wherein at least a portion of the reinforcing layer is a metallic matrix composite (MMC) material that includes reinforcing fibers. A turbine engine is also provided.

1 . A method for assembling a turbine engine assembly including a core engine, said method comprising:
 coupling a first rotor spool within the engine assembly, wherein the first rotor spool includes a first fan assembly coupled upstream from the core engine, an intermediate-pressure turbine coupled downstream from the core engine, and a first shaft coupled between the first fan assembly and the intermediate-pressure turbine;   coupling a second rotor spool within the engine assembly, wherein the second rotor spool includes a second fan assembly coupled upstream from the first fan assembly, a low-pressure turbine coupled downstream from the intermediate-pressure turbine, and a second shaft coupled between the second fan assembly and the low-pressure turbine; and   coupling a third rotor spool within the engine assembly, wherein the third rotor spool includes a compressor, a high-pressure turbine coupled upstream from the intermediate-pressure turbine, and a third shaft extending between the compressor and the high-pressure turbine, at least one of the first, second, and third shafts includes a first end, an opposing second end, and a tubular portion extending between the first and second ends, a reinforcing layer circumscribes a portion of the tubular portion wherein at least a portion of the reinforcing layer is a metallic matrix composite (MMC) material that includes reinforcing fibers.   
   
   
       2 . A method in accordance with  claim 1  further comprising:
 embedding the reinforcing fibers within the MMC material such that the reinforcing fibers extend substantially parallel to a centerline of at least one of the first, second, and third shafts; and   coupling a cladding substantially concentrically about the reinforcing layer.   
   
   
       3 . A method in accordance with  claim 1  further comprising embedding a plurality of continuous reinforcing fibers within the MMC material. 
   
   
       4 . A method in accordance with  claim 1  further comprising embedding at least one of a plurality of nano sized boron fibers and a plurality of boride fibers within the MMC material. 
   
   
       5 . A shaft for a turbine engine, said shaft comprising:
 a first end, an opposing second end, and a tubular portion extending therebetween;   a reinforcing layer circumscribing a portion of said tubular portion, said reinforcing layer comprising a metallic matrix composite (MMC) material including reinforcing fibers; and   a cladding circumscribing a portion of said reinforcing layer and said tubular portion.   
   
   
       6 . A shaft in accordance with  claim 5  wherein said shaft is coupled within at least one of a single-spool gas turbine engine, a two-spool gas turbine engine, a multi-spool gas turbine engine, a FLADE engine, a variable cycle (VCE) gas turbine engine, an adaptive cycle (ACE) gas turbine engine, and a turbine-based combined cycle (TBCC) engine. 
   
   
       7 . A shaft in accordance with  claim 5  wherein said shaft is a power take-off shaft. 
   
   
       8 . A shaft in accordance with  claim 5  wherein said tubular portion is fabricated with a titanium-based alloy and said cladding is fabricated with a titanium-based alloy. 
   
   
       9 . A shaft in accordance with  claim 5  wherein said shaft has an axis of elongation wherein said reinforcing fibers extend substantially parallel to the axis of elongation. 
   
   
       10 . A shaft in accordance with  claim 5  wherein said reinforcing fibers are arranged in at least one ply, said reinforcing fibers comprise at least one of nano-sized Boron and Boride fibers dispersed within said MMC material. 
   
   
       11 . A shaft in accordance with  claim 10  wherein at least one of said Boron and Boride fibers are dispersed within said MMC using at least one of external doping and solid free forming techniques. 
   
   
       12 . A shaft in accordance with  claim 5  wherein said MMC material comprises at least one of titanium, nickel, steel, and aluminum. 
   
   
       13 . A counter-rotating, multi-spool turbine engine comprising:
 a first rotor spool comprising a fan assembly, a low-pressure turbine, and a first shaft, said fan assembly is coupled upstream from said high-pressure compressor, said low-pressure turbine is coupled downstream from said high-pressure turbine; and   a second rotor spool comprising an intermediate-pressure compressor, an intermediate-pressure turbine, and a second shaft, said intermediate-pressure compressor is coupled between said high-pressure compressor and said fan assembly, said intermediate-pressure turbine is coupled between said high-pressure turbine and said low-pressure turbine, said first shaft extending between said fan assembly and said low-pressure turbine, said second shaft extending between said intermediate-pressure compressor and said intermediate-pressure turbine, a portion of at least one of said first and second shafts is fabricated using a metallic matrix composite (MMC) material including reinforcing fibers embedded therein.   
   
   
       14 . A gas turbine engine in accordance with  claim 13  further comprising a third rotor spool comprising a high-pressure compressor, a high-pressure turbine coupled downstream from said high-pressure compressor, and a third shaft extending therebetween. 
   
   
       15 . A gas turbine engine in accordance with  claim 14  wherein at least one of said first, second, and third shafts comprises a first end, an opposing second end, and a tubular portion extending therebetween, a reinforcing layer circumscribes a portion of said tubular portion wherein said reinforcing layer comprises said MMC material including said reinforcing fibers, and a cladding circumscribing a portion of said reinforcing layer and said tubular portion. 
   
   
       16 . A gas turbine engine in accordance with  claim 15  wherein said tubular portion is fabricated with a titanium-based alloy, said cladding is fabricated with a titanium-based alloy. 
   
   
       17 . A gas turbine engine in accordance with  claim 13  wherein said reinforcing fibers comprise continuous silicon carbine fibers arranged in at least one ply. 
   
   
       18 . A gas turbine engine in accordance with  claim 13  further comprising a FLADE duct circumscribing said core engine, said FLADE duct comprises at least one FLADE coupled to at least one of said first and second fan assemblies. 
   
   
       19 . A gas turbine engine in accordance with  claim 13  further comprising a fan variable area bypass injector (VABI) coupled downstream from said fan assembly and upstream from said core engine wherein said VABI is configured to provide variable bypass flow to said core engine.